1) We and our collaborators have screened multiple anti-sense oligonucleotides for efficacy in reducing PrPC expression in the brain tissue of mice and in tissue cultures cells. The best candidates have proven to significantly reduce PrPC mRNA and protein expression in the brains of mice animals for extended periods of time after treatment. They also reduce the accumulation of PrPSc in scrapie-infected tissue culture cells. Both prophylactic and post-exposure treatments of mice inoculated with scrapie are ongoing.